Conventionally, as is the case with planetary gears in a planetary gear mechanism that is used in a deceleration mechanism, components that are formed by a rotation transmission member such as a gear member or the like and a columnar shaped member such as a bearing or the like are fixed by a device such as a key slot, a spline, a knurl, or by pressure insertion or the like such that the two members are not rotated relative to each other by rotation force.
However, because a configuration such as a key slot and spline needs to be formed in both an inner circumferential surface and an outer circumferential surface of each member, the problem arises in that manufacturing costs are high. Moreover, in the case of a key slot, it is necessary to separately manufacture the three key members and then assemble these members so that the problem arises that assembly costs are further accumulated.
In addition, because an anti-release function cannot be obtained from simple pressure insertion, key slots, splines, and flat knurls, they cannot be used in rotation transmission members that receive force in the thrust direction. Furthermore, zigzag knurls that do have an anti-release function have a configuration that cannot be formed by normal powder press-molding. Because powder metallurgical production cannot be employed, zigzag knurls are not suitable for bearings and gears that are demanded in large volume production and at low cost.